Switch actuator lock for push button switches

ABSTRACT

An improved lock for preventing accidental actuation of a push button switch. The switch includes an actuating button mounted to slide in a housing between a released position and an actuated position. A substantially U-shaped locking member is attached to the sides of the button to pivot between locked and released positions. When the locking member is in the locked position, tabs project towards the housing to prohibit movement of the button to the actuated position by abutting the housing. A lip projects from the locking member to facilitate pivoting of the locking member to the released position.

United States Patent Weinhart May 30, 1972 [54] SWITCH ACTUATOR LOCK FOR PUSH 3,388,224 6/1968 Higgins ..200/42 T BUTTON SWITCHES Primary Examiner-Herman .l. Hohauser [72] Inventor: Rudolf Weinhart, Inglewood, Calif. A"0mey Owen & Owen [73] Assignee: Master Specialties Company Costa Mesa,

calm 57 ABSTRACT [22] Filed; Feb. 17 1971 An improved lock for preventing accidental actuation of a push button switch. The switch includes an actuating button PP 116,034 mounted to slide in a housing between a released position and an actuated position. A substantially U-shaped locking member is attached to the sides of the button to pivot between E (gill locked and released positions. when the locking member is in 58] Fieid 42 42 T 44 the locked position, tabs project towards the housing to prohibit movement of the button to the actuated position by abutting the housing, A lip projects from the locking member [56] References Cited to facilitate pivoting of the locking member to the released UNITED STATES PATENTS Position- 3,214,530 10/1965 Tharp et a1. ..200/42 T 7 Claims, 6 Drawing Figures Patented May 30, 1972 3,666,901

INVENTORZ RUE ELF PI EJNHAH T.

SWITCH ACTUATOR LOCK F OR PUSH BUTTON SWITCHES BACKGROUND OF THE INVENTION DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGS. 1-4, a push button indicator switch 10 is shown adapted with a locking member 1 1 constructed in accordance to the resent invention. The indicator 10 in- Thrs invention relates to switches and more particularly to p an improved lock for preventing accidental actuation of push button switches.

Push button switches are used to perform many functions in instruments, controls, and the like. Such switches may be of a momentary contact type, of a momentary break type or of a snap action type in which a circuit is alternately made and broken during repeated actuations of the switch. Push button switches typically have a small round actuating button or, in a more complex embodiment, they may have an illuminated, rectangular actuating button bearing a printed message.

Push button switches, and in particular illuminated indicator switches, are commonly used in control panels for computers and for manufacturing processes. If a switch is accidentally actuated at the wrong time, serious damage may result. In extreme cases, the inadvertent actuation of a switch controlling a manufacturing process may endanger lives of employees. The hazard of accidental actuation is increased by the fact that indicator switches are often mounted in groups with a large number of switches located in a relatively small area on a control panel. Accordingly, it is often desired to provide a guard for preventing accidental actuation of critical switches. Covers are commonly placed over the critical switches to prohibit actuating the switches until the cover is either removed or pivoted out of the way.

SUMMARY OF THE INVENTION According to the present invention, an improved lock is provided for preventing the accidental actuation of push button switches. The push button switches are of the type including an actuating button mounted to slide in a housing between a released position and an actuated position. The button typically has a surface which extends from the switch housing and is adapted to be pushed by an operators finger. The lock generally comprises a substantially U-shaped locking member which is pivotally attached to opposite sides of the push button by means of a pair of pivot pins. The locking member is mounted to pivot between a locked position, wherein the push button is prohibited from movement to the actuated position, and a released position, wherein the actuating button is free to move to the actuated position. When the locking member is in the locked position, a pair of tabs project from the'locking member to interfere with the housing, thus restricting movement of the actuating button. By pivoting the locking member to the released position, the tabs are pivoted away from the housing, permitting movement of the button. A lip is also formed on the locking member to facilitate pivoting the locking member to the released position.

Accordingly, it is a preferred object of the invention to provide an improved lock for preventing accidental actuation of a push button switch.

Other objects and advantages of the invention will become apparent from the following detailed description, reference being made to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front elevational view of a push button indicator switch including a lock constructed in accordance with the present invention;

FIG. 2 is a cross-sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1;

FIG. 4 is a cross-sectional view similar to FIG. 3 but showing the locking member pivoted to the released position;

FIG. 5 is a perspective view of the locking member; and

FIG. 6 is a perspective view of a modified embodiment of the locking member.

cludes a housing 12 mounted in a panel 13 by conventional techniques. A switch actuating push button 14 is mounted to slide between a released position, as shown in solid in FIGS. l-4, to an actuated position, as shown in dashed lines in FIG. 4. The push button 14 may be attached by means of a shaft 15 to a circuit board (not shown) which mounts a plurality of lamps for illuminating the push button 14. In such a case, the push button 14 may be pulled out of the housing 12 for relarnping. The shaft 15 also functions to actuate a conventional switch (not shown). The switch may, for example, be of the momentary contact type, of the momentary break type or of the snapped action type. A typical illuminated indicator switch of this type is shown in detail in U.S. Pat. No. 3,090,949 to Don M. Hallerberg.

As shown in FIG. 1, the housing 12 has a generally rectangular opening 16 and the push button 14 has a similar rectangular shape to slide within the housing opening 16. The locking member 1 l, which is shown in detail in FIG. 5, is substantially U-shaped having spaced end portions 17 for receiving the button 14 therebetween. A pivot pin 18 projects from each end portion 17 for engaging a hole 19 in a side 20 of the button 14. As shown in FIG. 5, the pivot pins 18 are attached to the end portions 17 by welding or other conventional techniques. The pivot pins 18 permit the locking member 11 to pivot between a locked position, as shown in FIGS. 1-3, and a released position, as shown in FIG. 4. When the locking member 1 1 is in the locked position, a pair of tabs 21 project from the end portions 17 of the locking member 11 towards the housing 12. When an operator attempts to push the button 14 towards the actuated position, the tabs 21 abut and interfere with the housing 12 to prevent movement of the button 14. When, on the other hand, the locking member 11 is pivoted to the released position, as shown in FIG. 4, the tabs 21 are pivoted away from the housing 12 to permit movement of the button 14 into the housing 12 for actuating the switch.

The locking member 11 may also be provided with a stop 22. The stop 22 is spaced from the end portions 17 of the locking member 11 and projects towards the housing 12 when the locking member 1 1 is in the locked position. The stop 22 is adapted to abut either the housing 12 or the panel 13 for limiting pivotal movement of the locking member 11 in the locked position. A hooked lip 23 is also provided on the locking member I l spaced from the stop 22. The lip 23 is adapted to be engaged by the fingernail of a switch operator to facilitate pivoting the locking member I I to the released position.

Referring now to FIG. 6, a modified embodiment of the locking member 25 is shown. The locking member 25 is also substantially U-shaped to conform to the push button 14 of the indicator 10 of FIGS. 1-4. End portions 26 of the locking member 25 are bent inwardly and shaped to define a pair of spaced, coaxially aligned pivot pins 27 for pivotally engaging a switch actuator button. A lip 28 is also formed on the locking member 25, as well as a pair of tabs 29 and a stop 30.

In a further modification of the locking member (not shown), the pivot pins may be mounted directly in the switch button 14. Openings are then formed in the spaced end portions of the locking member to receive the pivot pins. The locking member then pivots on the pins.

It will be appreciated that various modifications and changes may be made to the locking member and that the locking member may be modified for use on push button switches differing from the type shown in the accompanying drawing without departing from the spirit and the scope of the appended claims.

What I claim is:

1. In a push button switch having a switch actuating button mounted for lineal movement towards and away from a housing between a released position and an actuated position, said button having a surface adapted to be pushed to actuate said switch, an improved lock comprising a generally U-shaped locking member having two end portions spaced for receiving said button therebetween, means mounting said locking member on said button to pivot between a locked position and a released position, said mounting means pivotaily attaching said end portions of said locking member to said button, and a tab projecting from said locking member from adjacent one of said end portions, said tab projecting toward said housing when said locking member is in said locked position to prohibit movement of said button towards said housing to the actuated position and, when said locking member is pivoted to said released position, said tab projecting away from said housing to permit movement of said button to the actuated position.

2. In a push button switch, an improved look, as set forth in claim 1, wherein said tab comprises a pair of tabs projecting from said locking member, one tab projecting from adjacent each of said end portions, each of said tabs abutting said housing to prohibit actuation of said switch when said locking member is in said locked position.

3. In a push button switch, an improved lock, as set forth in claim 1, wherein said mounting means includes a pair of pivot pins and means attaching a different one of said pivot pins to each of said end portions with said pivot pins projecting towards each other and coaxially aligned for engaging said button.

4. In a push button switch, an improved lock, as set forth in claim 1, wherein said mounting means includes a pair of pivot pins integrally formed on said end portions with said pivot pins projecting towards each other and coaxially aligned for engaging said button.

5. In a push button switch, an improved lock, as set forth in claim 1, wherein said locking member is located below said button surface when in the locked position, and further including a lip integrally formed on said U-shaped locking member, said lip being spaced from said end portions to facilitate pivoting said locking member to said released position.

6. In an indicator switch including a switch actuating button with a flat indicating surface adapted to be pushed to actuate said switch, said button moving in a housing between a released position and an actuated position, an improved lock comprising a generally U-shaped locking member having two end portions spaced to receive said button therebetween, a pair of pivot pins attaching said end portions to said button whereby said locking member pivots between a locked position and a released position, a pair of tabs, one projecting from each end portion of said locking member toward said housing when said locking member is in said locked position to prohibit movement of said button to the actuated position by abutting said housing and, when said locking member is pivoted to said released position, said tabs projecting away from said housing to permit movement of said button to the actuated position.

7. In an indicator switch, an improved lock, as set forth in claim 6, and including a lip integrally formed on said U-shaped locking member, said lip being spaced from said end portions to facilitate pivoting said locking member to said released position. 

1. In a push button switch having a switch actuating button mounted for lineal movement towards and away from a housing between a released position and an actuated position, said button having a surface adapted to be pushed to actuate said switch, an improved lock comprising a generally U-shaped locking member having two end portions spaced for receiving said button therebetween, means mounting said locking member on said button to pivot between a locked position and a released position, said mounting means pivotally attaching said end portions of said locking member to said button, and a tab projecting from said locking member from adjacent one of said end portions, said tab projecting toward said housing when said locking member is in said locked position to prohibit movement of said button towards said housing to the actuated position and, when said locking member is pivoted to said released position, said tab projecting away from said housing to permit movement of said button to the actuated position.
 2. In a push button switch, an improved lock, as set forth in claim 1, wherein said tab comprises a pair of tabs projecting from said locking member, one tab projecting from adjacent each of said end portions, each of said tabs abutting said housing to prohibit actuation of said switch when said locking member is in said locked position.
 3. In a push button switch, an improved lock, as set forth in claim 1, wherein said mounting means includes a pair of pivot pins and means attaching a different one of said pivot pins to each of said end portions with said pivot pins projecting towards each other and coaxially aligned for engaging said button.
 4. In a push button switch, an improved lock, as set forth in claim 1, wherein said mounting means includes a pair of pivot pins integrally formed on said end portions with said pivot pins projecting towards each other and coaxially aligned for engaging said button.
 5. In a push button switch, an improved lock, as set forth in claim 1, wherein said locking member is located below said button surface when in the locked position, and further including a lip integrally formed on said U-shaped locking member, said lip being spaced from said end portions to facilitate pivoting said locking member to said released position.
 6. In an indicator switch including a switch actuating button with a flat indicating surface adapted to be pushed to actuate said switch, said button moving in a housing between a released position and an actuated position, an improved lock comprising a generally U-shaped locking member having two end portions spaced to receive said button therebetween, a pair of pivot pins attaching said end portions to said button whereby said locking member pivots between a locked position and a released position, a pair of tabs, one projecting from each end portion of said locking member toward said housing when said locking member is in said locked position to prohibit movement of said button to the actuated position by abutting said housing and, when said locking member is pivoted to said released position, said tabs projecting away from said housing to permit movement of said button to the actuated position.
 7. In an indicator switch, an improved lock, as set forth in claIm 6, and including a lip integrally formed on said U-shaped locking member, said lip being spaced from said end portions to facilitate pivoting said locking member to said released position. 